Iron bending machine



Jan. 14, 1947.

A. HOSSFELD IRON BENDING MACHINE Filed Mays, 1944 M5@ se. 2 i (MW j Patented Jan. 14, 1947 UNITED STATES PATENT OFFICE IRON BENDING MACHINE Albert Hossfeld, Winona, Minn. Application Mil-y 3, 1944, Serial No. 533,963

1 Claim. 1

My present invention relates to improvements in iron bending machines of the type disclosed and broadly claimed in my United States Letters Patent No. 1,832,210, issued November 17, 1931, and entitled Die for bending angle bars.

The objects of this invention are: rst, to provide a simple and highly efcient machine for bending a at metal bar in the plane thereof; second, for holding the bar from buckling while bending the same; and third, to permit free endwise feeding movement of the bar in the machine when the bending pressure is removed therefrom.

To the above end, generally stated, the invention consists of the novel devices and combination of devices hereinafter disclosed and claimed.

In the accompanying drawing, which illustrates the invention, like characters indicate like parts throughout the several views.

Referring to the drawing:

Fig. 1 is a fragmentary plan view of the im proved iron bending machine, Isome parts being shown in section;

Figs. 2 and 3 are views in vertical section taken on the line 2 2 and the irregular line 3-3 of Fig. 1; and

Fig. 4 is a bottom plan view of the radius block.

The improved bending machine includes a stationary main frame 5 and a swinging bending frame 6 attached to said main frame by a pivot pin 'I for horizontal swinging movement. Said main frame 5 is rigidly secured to a bench or other support, not shown, by a plurality of nutequipped bolts 8.

Each frame 5 and 6 includes a pair of vertically spaced fiat bars 9 and Ill, respectively. The inner end portions of the bars I0 of the swinging frame B are interposed between the adjacent ends of the bars 9 of the main frame 5 with a close working fit. The pivotV pin l extends through aligned holes in the bars 9 and i. A hand lever, not shown, is attached to the outer ends of the bars I9 for use in swinging the frame 6.

A master die II is interposed between the bars I0 and pivotally secured to the pairs of bars 9 and I0 by the pivot pin 1. Integral with the master die II is a pair of forwardly projecting wedge-acting members I2. Also integral with the master die II is a forwardly projecting worksupporting table I3, located bel-ow the wedgeacting members I2. The outer faces of the master die II and the outer edge of the work-supporting table I3 are on arcs of concentric circles.

Co-operating with the master die II is a radius block I4, the front and back thereof being on arcs of circles that are concentric with the face of the master die II. This radius block I4 is positioned over the work-supporting table I3 and has in its back a pair of notches I5 into which the wedge-acting members I2 project. The bottoms of the notches I5 are upwardly and outwardly inclined and slidably engage the oblique under 'surfaces I5 of the wedge-acting members I 2. On the under side of the radius block I4 is a curved rib-like stop member I 'I that is integral with said block and affords a base of resistance for a nat iron bar :v resting flatwise on the work-supporting table I3 and being bent in the plane thereof. Or in other words, the stop member Il takes the thrust of the bending pressure applied to the bar x by the bending block I9. This stop member I'I is on a segment of a circle that is concentric with the front and back surfaces of the radius block I4.

A stop block I8 on the main frame 5 is provided for holding the bar a: against the stop member I'i and a bending block I9 is mounted on the swinging frame I5. These two blocks I8 and I9 are identical, the one with the other. The stop block I 8 extends between the bars 9 and is secured thereto by a pivot pin 29. This pivot pin 20 extends through one pair of a plurality of longitudinally spaced holes 2l in the bars 9.

The bending block I9 is interposed between the bars Ill of the swinging frame 6 and secured thereto by a pivot pin 22. The pivot pin extends through one pair of longitudinally spaced holes 23 in said bars.

As shown, the left-hand end portion of the bar has been bent around the stop member Il on the arc of a circle havingV the same radius as the engaged edge of said member. The other end portion of the bar a: is straight. This bar :z: rests on the work-supporting table I3 and, in

turn, the radius block I4 rests on the bar :12. It is important to note that the radius block I4 is out of contact with the master die II and its stop member I'I is out of contact with the work-supporting table I3.

It will be noted that the bar at its outer edge, engages the stop block I8 and is held thereby against the stop member I'I. The bending block I9 is in engagement with the outer edge of the straight portion of the bar .r and considerably in advance of the curve in said bar.

Obviously, by pulling the swinging frame 6 toward the bar :11, said bar will be bent in the plane thereof by the contacting bending block I9 around the curved stop member I'I. During bending of the bar zu, the pressure thereof on the stop member I'I will force radius block I4 toward the master die I I. As the radius block I4 moves toward the master die I I, the engagement of said radius block I4 with the wedge-acting members I2 will force the radius block I4 downwardly onto the underlying bar It will thus be seen that the bar :l: will be tightly clamped ilatwise between Work-supporting table I3 and the radius block I4 and thereby prevent buckling of the bar :I: during bending thereof.

The above described iron bending machine will,V

In a device of the class described, a die having a work table for Isupporting thereon a flat piece of metal to be bent on the arc of a circle, a radius block overlying the table to be supported on the bar and having on its under side a stop shoulder` to be engaged by the bar at its inner edge, and holding the bar with its outer edge portion outwardly of the die and the radius block, the faces of the die and radius block and the stop shoulder being on the arcs of circles, the width of the stop A shoulder being less than the thickness of the bar,

whereby said stop shoulder is out of engagement with the table, a stop to be engaged by the bar at its outer edge for holding said bar with its inner edge against the stop shoulder, a bending device operative on the outer edge of the bar in advance of the stop for bending the bar on the stop shoulder, and means actuated by pressure generated by bending the bar to force the radius block onto the bar and clamp the same onto the table.

ALBERT HOSSFELD. 

